I’m a little shaky on IPA, & I’m using Wikipedia’s markup symbols some of which I may have misread, but English orthography is pretty much vague, so here:
successful: |sʌk ˈsɛs fl| (but there’s not really a rest between the first two syllables so I’m not sure where to put the accent mark–I suppose could attach the |k| to the |s| sometimes.)
acceleration: |ək ˌsɛl ə ˈɹei ʃən| (heading toward something like |æk ˌsɛl œ ˈɹei ʃʌn| if emphasized–but the first “a” could be an |ɛ| or even dropped)
eccentric: |ɛk ˈsɛn trɪk| , sometimes schwa-ing or dropping the first vowel.
Raised on radio. That is, sort of a suburban educated southern Missouri with Iowa & Ohio influences, then a lot of overlay from standardized North American & International English forms.
Or in short, sort of a nerdy midwestern.
ETA: I may agree with the poster who says it’s an “x.”
I have also heard “flaccid” with no |k| & seem to have been taught to say it that way.
Dropping the |k| from “acceleration”, “successful”, & “eccentric” sounds something I’ve heard but don’t do. I don’t correct people if they do, it’s just an odd thing that sounds like a not-like-me cultural marker. I wouldn’t marry a woman who did it.
Drumroll is 8 miles out of Hell. You can’t miss it. Trumpet Flair is 60 miles from Ypsilanti by seaplane. By car, it’s 302 miles. Incredible walleye fishing there. 
Do they also pronounce “accessories” as “assessories”? I’ve heard the latter on TV a few times.
suck SESS full, uck CELL er A shun, and eck SEN trik
Born & bred in SF, CA.
If I may borrow a phrase, these guys are so white they make Bryant Gumbel look like Flavor Flav.
Suck- SESS- full
Ack sell er A shun
Eck SEN trick
North Carolina, plus everyplace else.